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Is it bad to cut the factory plastic battery covers so I can check waterlevel?

Removal of tops from battery covers from to facilitate water level check and adding water.

What motivates this desire? maintiance free means just that. Are you having problems with battery life?

I have two batteries (at $80. each) in my diesel and they are not maintenance free. When I check them they are low on water . They last about 4 to 5 years this way. Alternator punches out 14.4 volts. I live in Central Texas summer day temps are 98 degrees.

If you have the old fashioned batteries that need water added the caps should be easily removed and water can be added up to the rings as needed. I have an electric golf kart that uses the old add water style batteries and it has battery caps that snap in place. I even found one of the old fashioned filler bottles at NAPA that has the special gizmo that fills the batteries up to the proper level automatically. Hadn’t seen one of these in about 15 years but good ole NAPA still had one to sell me.

I don’t understand why you are asking the question? If it is a maintenance free battery cutting the caps off and adding water is not good for the battery. These batteries use an electrolyte gel, not water.

If the battery has screw on or snap on caps then you are supposed to add water as a normal part of battery maintenance. It is just that almost all batteries for cars and trucks sold these days are the maintenance free type.

Specialty batteries for motorcycles, ATV’s, deep discharge marine, and golf carts are sometimes maintenance free and sometimes old style with sulfuric acid and need water levels topped off.

It should not be hard to tell one type of battery from the other.

If your batteries are not maintiance free you need a way to provide them maintiance.

The way they explained the principle of maintenance-free batteries to me in an electrical school a jillion years ago is the following.
Maintenance-free batteries are designed with compartments in the upper case of the battery. Acid will not evaporate but water does. The evaporating water condenses in the upper compartments and drips back down into the acid/water electrolyte solution.
This assures a constant supply of water and the proper ratio of water/acid at all times.

Cut the case and it will likely never seal properly again. I would not do it.
You say the system charges at 14.4 volts. That sounds a bit on the high side to me so maybe a slight overcharging is responsible for the water loss.

Water in batteries does not “evaporate”… It is broken down into hydrogen and oxygen. When being charged, pressure builds up and is vented, resulting in fluid loss. In flooded cell lead acid batteries, even so called “maintenance free” types are vented and can lose electrolyte, more so in hot climates. Even AGM and Gel batteries dry out over time and heavy use.

Battery manufacturers have sealed their consumer batteries more to reduce liability problems than anything else. Since the batteries designed life is around 5 years, they have found adding water can be eliminated without shortening the batteries life very much. In “hot” climates, the batteries they sell have a slightly lower specific gravity to better resist the heat and extend their life a little…

Now I know why some batteries are sold for northern climates and other for southern. Makes sense, thanks.

Evaporation is probably a bad choice of words to describe it. Boiling off, outgassing, or whatever would probably be a better term.
The point being that the water is constantly being recycled in the battery with no or extremely little loss of water due to the battery design.

I had to listen to a heavily accented (and humorless) German field instructor drone on almost non-stop for close to 4 hours about how an automotive battery works. After the first 2 it became a bit mind-numbing. :slight_smile:

It seems to me if the OP is losing water constantly on non-maintenance free batteries that the 14.4 volts may be the contributing factor behind this rather than a battery fault since that figure is at the upper end of the charging scale.
This would be especially true if 14.4 is showing when electrical items are in use. (cabin fan, A/C, lighting, wipers, etc.)

upon rereading my initial message it could be construed I’m cutting off the caps ,I’m not.I’m referring to the large plastic box that covers the entire battery. To remove the box one must remove the cables and then the box. A lot of work when I only wish to check the battery and I loose computer settings on assorted accessories on the truck… What I have done is cut the top of the box over the filler holes ( about 1" X 7") and replace the box as it must be protection to the battery from heat!?

Re the 14.4 .There are two batteries on board and they use water. I check them when cool(condensation ,I learned something new (thank you)

Thanks for the info .I learn a little more every time I read something on a subject.Now if I can just not forget it.

Thanks for that little tidbit ,too. I see very few SEALED batteries around here ,Central Texas. Maybe it is a climate thing…Thanks again…I have a large tractor, two pick ups and even my wife’s Ford 09 Edge and they all have a water based solution with removable inspection caps…
thanks and regards to all who responded…

What I have done is cut the top of the box over the filler holes ( about 1" X 7") and replace the box as it must be protection to the battery from heat!?

Underhood dress-up, protect the posts from accidental shorting, keep the top of the battery clean, added crash protection and spill control in the event of a battery explosion or broken case…

That’s what I thought you meant. Cut it off and MacGyver a top to protect it from the heat. If it were me I’d get another battery cover from a junkyard, cut off the top so that it sits on top of the battery, and stretch-strap it on to protect it from the hot sun/heat. Rocketman

Thanks for the knowledge byte on condensation ,that’s cool…

Thank you Rocketman…
I appreciate the info and creative thinking…Heat is big here in the summer ,so I pop the hood and park under a big tree after a drive…My wife think I’m nuts but I figure it helps slow down the heat damage to the plastic, rubber , and other soft materials under the hood…(can’t hurt!?)

I am dealing with the AZ summer heat (also with a FORD) and don’t feel its necessary to take such action,to each his own.

I did suspect you were talking about cutting up the cover that prevents access to the maintiance free or maintiance fill caps. You let the confusion run quite a while.

  My bad.......I'm old.....

In recombinant lead-acid batteries the hydrogen and oxygen that is produced as the battery cycles is used to regenerate water. I don’t know if this used in automotive starting batteries. It is used in all valve-regulated